Browsing by Subject "LPS"

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  • Lindfors, S; Polianskyte-Prause, Z; Bouslama, R; Lehtonen, E; Mannerla, M; Nisen, H; Tienari, J; Salmenkari, H; Forsgard, R; Mirtti, T; Lehto, M; Groop, PH; Lehtonen, S (2021)
    Aims/hypothesis Chronic low-grade inflammation with local upregulation of proinflammatory molecules plays a role in the progression of obesity-related renal injury. Reduced serum concentration of anti-inflammatory adiponectin may promote chronic inflammation. Here, we investigated the potential anti-inflammatory and renoprotective effects and mechanisms of action of AdipoRon, an adiponectin receptor agonist. Methods Wild-type DBA/2J mice were fed with high-fat diet (HFD) supplemented or not with AdipoRon to model obesity-induced metabolic endotoxaemia and chronic low-grade inflammation and we assessed changes in the glomerular morphology and expression of proinflammatory markers. We also treated human glomeruli ex vivo and human podocytes in vitro with AdipoRon and bacterial lipopolysaccharide (LPS), an endotoxin upregulated in obesity and diabetes, and analysed the secretion of inflammatory cytokines, activation of inflammatory signal transduction pathways, apoptosis and migration. Results In HFD-fed mice, AdipoRon attenuated renal inflammation, as demonstrated by reduced expression of glomerular activated NF-kappa B p65 subunit (NF-kappa B-p65) (70%, p < 0.001), TNF alpha (48%, p < 0.01), IL-1 beta (51%, p < 0.001) and TGF beta (46%, p < 0.001), renal IL-6 and IL-4 (21% and 20%, p < 0.05), and lowered glomerular F4/80-positive macrophage infiltration (31%, p < 0.001). In addition, AdipoRon ameliorated HFD-induced glomerular hypertrophy (12%, p < 0.001), fibronectin accumulation (50%, p < 0.01) and podocyte loss (12%, p < 0.001), and reduced podocyte foot process effacement (15%, p < 0.001) and thickening of the glomerular basement membrane (18%, p < 0.001). In cultured podocytes, AdipoRon attenuated the LPS-induced activation of the central inflammatory signalling pathways NF-kappa B-p65, c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38-MAPK) (30%, 36% and 22%, respectively, p < 0.001), reduced the secretion of TNF alpha (32%, p < 0.01), and protected against podocyte apoptosis and migration. In human glomeruli ex vivo, AdipoRon reduced the LPS-induced secretion of inflammatory cytokines IL-1 beta, IL-18, IL-6 and IL-10. Conclusions/interpretation AdipoRon attenuated the renal expression of proinflammatory cytokines in HFD-fed mice and LPS-stimulated human glomeruli, which apparently contributed to the amelioration of glomerular inflammation and injury. Mechanistically, based on assays on cultured podocytes, AdipoRon reduced LPS-induced activation of the NF-kappa B-p65, JNK and p38-MAPK pathways, thereby impelling the decrease in apoptosis, migration and secretion of TNF alpha. We conclude that the activation of the adiponectin receptor by AdipoRon is a potent strategy to attenuate endotoxaemia-associated renal inflammation.
  • Karhu, Elisa (Helsingfors universitet, 2016)
    Gastrointestinal symptoms such as diarrhea, cramping, nausea and gastric pain occur frequently in runners during training and competitions. The mechanisms leading to the distress are not fully understood, nor the reason why some remain asymptomatic. However, hyperthermia induced by exercise elevation of core temperature and oxidative damage due to reduced gastric blood flow have been postulated to affect the intestinal epithelial cells. Both sources of stress disrupt the binding of the epithelial tight junction proteins and increase permeability of the membrane to luminal endotoxins. Endotoxins reaching the blood stream through leaky tight junctions lead to an inflammatory response mediated by cytokines. These mechanisms may underlie the gastrointestinal symptoms often experienced by endurance athletes. The aim of this study was to measure running-induced changes in intestinal permeability and inflammatory markers and investigate their association with gastrointestinal symptoms. A secondary objective was to inspect possible correlations between gastrointestinal symptom occurrence and intake of certain nutrients. A total of 17 active runners were allocated into a control group (asymptomatic) or a symptomatic group based on a symptom history questionnaire and completed a 90-minute running test. Intestinal permeability at baseline and after the run were assessed via urine recovery of orally administered Iohexol . LPS (endotoxin) and zonulin concentrations were determined from serum samples. Participants kept a food diary for three days before each measurement and filled out a symptom questionnaire after the run. No significant difference was found in intestinal permeability between symptomatic and asymptomatic runners either at rest or following strenuous exercise. However, both groups experienced a significant increase in intestinal permeability from baseline to after running. LPS concentrations were significantly higher at baseline in the symptomatic group. This may explain the higher symptom occurrence in the symptomatic group. Zonulin levels were higher in control group than symptom group after the run. Zonulin concentration was also higher in the control group after the run compared to baseline. The symptom group reported more stomach pain and stool changes after running compared to controls. Comparison of average intake of various nutrients between the two groups showed no significant differences, indicating an individual predisposition as the cause of symptoms rather than diet alone. The lack of difference in intestinal permeability between the groups combined with the difference in symptom occurrence indicates that intestinal permeability changes alone do not account for symptom development. A possible factor may be individual differences in intestinal mucosa repair ability or some underlying pathology.
  • Sali, Virpi; Veit, Christina; Valros, Anna; Junnikkala, Sami; Heinonen, Mari; Nordgreen, Janicke (2021)
    Infectious and inflammatory conditions are common especially in growing pigs. Lipopolysaccharide (LPS) is an important antigenic structure of Gram-negative bacteria and can be used to induce inflammation experimentally. As pigs are usually group-housed in commercial conditions, it is difficult to detect sick individuals, particularly at an early stage of illness. Acute phase proteins such as haptoglobin (Hp) are known indicators of an activated innate immune system whereas adenosine deaminase (ADA) is a relatively novel inflammatory biomarker in pigs. Both parameters can be measured in saliva and could be used as indicators of inflammation. Compared with blood sampling, saliva sampling is a less stressful procedure that is rapid, non-invasive and easy to perform both at group and at individual level. In this blinded randomized clinical trial, 32 female pigs at their post-weaning phase were allocated to one of four treatments comprising two injections of the following substance combinations: saline-saline (SS), ketoprofen-saline (KS), saline-LPS (SL), and ketoprofen-LPS (KL). First, ketoprofen or saline was administered intramuscularly on average 1 h before either LPS or saline was given through an ear vein catheter. In all groups, saliva was collected prior to injections (baseline) and at 4, 24, 48, and 72 h post-injection for determination of ADA, Hp, and cortisol concentrations. A multivariate model was applied to describe the dynamics of each biomarker. Pairwise relationships between ADA, Hp, and cortisol responses from baseline to 4 h post-injection within the SL group were studied with Spearman correlations. A significant increase in the SL group was seen in all biomarkers 4 h post-injection compared to baseline and other time points (pairwise comparisons, p < 0.01 for all) and ketoprofen alleviated the LPS effect. We found a significant positive correlation between ADA and Hp within the SL group (r = 0.86, p < 0.05). The primary and novel findings of the present study are the response of ADA to LPS, its time course and alleviation by ketoprofen. Our results support the evidence that ADA and Hp can be used as inflammatory biomarkers in pigs. We suggest further studies to be conducted in commercial settings with larger sample sizes.
  • Lorey, Martina B.; Rossi, Katriina; Eklund, Kari; Nyman, Tuula A.; Matikainen, Sampsa (2017)
    Gram-negative bacteria are associated with a wide spectrum of infectious diseases in humans. Inflammasomes are cytosolic protein complexes that are assembled when the cell encounters pathogens or other harmful agents. The non-canonical caspase-4/5 inflammasome is activated by Gram-negative bacteria-derived lipopolysaccharide (LPS) and by endogenous oxidized phospholipids. Protein secretion is a critical component of the innate immune response. Here, we have used label-free quantitative proteomics to characterize global protein secretion in response to non-canonical inflammasome activation upon intracellular LPS recognition in human primary macrophages. Before proteomics, the total secretome was separated into two fractions, enriched extracellular vesicle (EV) fraction and rest-secretome (RS) fraction using size-exclusion centrifugation. We identified 1048 proteins from the EV fraction and 1223 proteins from the RS fraction. From these, 640 were identified from both fractions suggesting that the non-canonical inflammasome activates multiple, partly overlapping protein secretion pathways. We identified several secreted proteins that have a critical role in host response against severe Gram-negative bacterial infection. The soluble secretome (RS fraction) was highly enriched with inflammation-associated proteins upon intracellular LPS recognition. Several ribosomal proteins were highly abundant in the EV fraction upon infection, and our data strongly suggest that secretion of translational machinery and concomitant inhibition of translation are important parts of host response against Gram-negative bacteria sensing caspase-4/5 inflammasome. Intracellular recognition of LPS resulted in the secretion of two metalloproteinases, a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) and MMP14, in the enriched EV fraction. ADAM10 release was associated with the secretion of TNF, a key inflammatory cytokine, and M-CSF, an important growth factor for myeloid cells probably through ADAM10-dependent membrane shedding of these cytokines. Caspase-4/5 inflammasome activation also resulted in secretion of danger-associated molecules S100A8 and prothymosin- in the enriched EV fraction. Both S100A8 and prothymosin- are ligands for toll-like receptor 4 recognizing extracellular LPS, and they may contribute to endotoxic shock during non-canonical inflammasome activation.
  • Satokari, Reetta (2020)
    The so-called Western diet is rich in saturated fat and sugars and poor in plant-derived fibers, and it is associated with an increased risk of metabolic and cardiovascular diseases, as well as chronic (low grade) inflammation. The detrimental effects of poor diet are in part mediated by gut microbiota, whose composition, functionality and metabolic end products respond to dietary changes. Recent studies have shown that high intake of sugars increase the relative abundance of Proteobacteria in the gut, while simultaneously decreasing the abundance of Bacteroidetes, which can mitigate the effects of endotoxin, as well as reinforce gut barrier function. Thus, a high sugar intake may stagger the balance of microbiota to have increased pro-inflammatory properties and decreased the capacity to regulate epithelial integrity and mucosal immunity. Consequently, high dietary sugar can, through the modulation of microbiota, promote metabolic endotoxemia, systemic (low grade) inflammation and the development of metabolic dysregulation and thereby, high dietary sugar may have many-fold deleterious health effects, in addition to providing excess energy.
  • Jian, Ching (Helsingfors universitet, 2016)
    Non-alcoholic fatty liver disease (NAFLD) is currently the most common liver disease in the western world. The human intestinal microbiota possesses enormous metabolic and immunomodulatory capabilities, and together with increased intestinal permeability, changes in the microbiota have been linked to the development of NAFLD. However, human studies so far have yielded contradictory findings regarding the compositional microbiota changes and provided little mechanistic understanding due to the predominance of cross-sectional studies. The aim of this study was to study human intestinal microbiota and gut permeability in NAFLD. Real-time PCR was employed to quantify the key intestinal bacterial groups in overweight or obese subjects with (n = 12) and without (n = 19) NAFLD, and in response to hypercaloric overfeeding, where participants were provided with three compositionally distinct diets to temporarily increase liver fat. In addition to the comparative analysis, the microbiota results were correlated to serum markers of intestinal permeability and metabolic endotoxemia, as well as clinical parameters related to NAFLD. The results show that host lipid metabolism and the gut microbiota, specifically Bacteroidetes and Clostridium cluster XIVa, are firmly intercorrelated. Bacteroidetes were found to be less abundant in subjects with NAFLD and correlate negatively with liver fat and serum triglycerides at baseline. Clostridium cluster XIVa, a dominant Firmicute group, was positively associated with serum triglycerides and pro-inflammatory markers but negatively with intestinal permeability. The relative abundance of Bacteroidetes as well as the markers of metabolic endotoxemia changed significantly in response to overfeeding, while no diet-induced systematic effects were found in Clostridium cluster XIVa, total bacteria, Escherichia coli group, Bifidobacterium or gut permeability. Our results based on a targeted microbiota analysis suggest that the role of the intestinal microbiota and gut permeability on triggering metabolic disarrangement and NAFLD in humans is inferior to other stimuli, such as diet.
  • Hiippala, Kaisa; Kainulainen, Veera; Suutarinen, Maiju; Heini, Tuomas; Bowers, Jolene R.; Jasso-Selles, Daniel; Lemmer, Darrin; Valentine, Michael; Barnes, Riley; Engelthaler, David M.; Satokari, Reetta (2020)
    Altered intestinal microbiota is associated with systemic and intestinal diseases, such as inflammatory bowel disease (IBD). Dysbiotic microbiota with enhanced proinflammatory capacity is characterized by depletion of anaerobic commensals, increased proportion of facultatively anaerobic bacteria, as well as reduced diversity and stability. In this study, we developed a high-throughput in vitro screening assay to isolate intestinal commensal bacteria with anti-inflammatory capacity from a healthy fecal microbiota transplantation donor. Freshly isolated gut bacteria were screened for their capacity to attenuate Escherichia coli lipopolysaccharide (LPS)-induced interleukin 8 (IL-8) release from HT-29 cells. The screen yielded a number of Bacteroides and Parabacteroides isolates, which were identified as P. distasonis, B. caccae, B. intestinalis, B. uniformis, B. fragilis, B. vulgatus and B. ovatus using whole genome sequencing. We observed that a cell-cell contact with the epithelium was not necessary to alleviate in vitro inflammation as spent culture media from the isolates were also effective and the anti-inflammatory action did not correlate with the enterocyte adherence capacity of the isolates. The anti-inflammatory isolates also exerted enterocyte monolayer reinforcing action and lacked essential genes to synthetize hexa-acylated, proinflammatory lipid A, part of LPS. Yet, the anti-inflammatory effector molecules remain to be identified. The Bacteroides strains isolated and characterized in this study have potential to be used as so-called next-generation probiotics.
  • Kyllönen, Hanna-Kaisa (Helsingin yliopisto, 2021)
    Tässä kirjallisuuskatsauksessa tarkastellaan lipopolysakkaridin (LPS) vaikutuksia immunologisiin parametreihin sekä vieroitetun porsaan immunologisia ja kehityksellisiä piirteitä, jonka vuoksi ne ovat alttiita sairastumaan tulehduksellisiin sairauksiin. Vieroitus tuotanto-olosuhteissa aiheuttaa porsaille stressiä ympäristön, ruokinnan ja sosiaalisten muutosten vuoksi. Porsaat ovat alttiita sairastumaan vieroituksen jälkeiseen ripuliin, sillä niiden immuunipuolustus ja suolisto ovat vielä kehittymässä vieroituksen aikaan. Vieroitusripulia aiheuttavia taudinaiheuttajia Suomessa ovat etenkin Escherichia coli, Brachyspira pilosicoli ja Lawsonia intracellularis, jotka ovat gram-negatiivisia bakteereja. Suolistotulehdukset aiheuttavat taloudellista haittaa sikataloudelle ja heikentävät eläinten hyvinvointia. Bakteeri-infektioiden hoidon seurauksena lisääntynyt antibioottien kulutus edistää antibioottiresistenssin kehittymistä. LPS on gram-negatiivisen bakteerin solukalvon ulompi osa, joka aktivoi voimakkaasti luontaista immuunipuolustusta. Lipopolysakkaridin seurauksena tulehdusta edistävien sytokiinien, kuten interleukiini-6:n, tuumorinekroositekijä alfan ja interleukiini-1 beetan pitoisuudet kohoavat nopeasti LPS-altistuksen jälkeen. Tämä johtaa akuutin vaiheen vasteen käynnistymiseen ja akuutin vaiheen proteiinien tuotantoon. Sian tärkeimmät akuutin vaiheen proteiinit ovat haptoglobiini, porcine major acute phase protein, C-reaktiivinen proteiini ja seerumin amyloidi A, joiden pitoisuutta voidaan mitata verestä tai syljestä. LPS vaikuttaa myös muiden immunologisten parametrien kuten adenosiinideaminaasin (ADA) pitoisuuteen. ADA:n pitoisuutta voidaan käyttää akuutin vaiheen proteiinien tapaan sairaiden eläinten tunnistamiseen sekä eläinten terveydentilan ja hyvinvoinnin arvioinnin tukena. Lisäksi LPS vaikuttaa kortisolin tuotantoon. Eri immunologisten parametrien vasteiden kestot LPS-altistuksen jälkeen voivat kuitenkin vaihdella.
  • Hiippala, Kaisa; Barreto, Gonçalo; Burrello, Claudia; Diaz-Basabe, Angelica; Suutarinen, Maiju; Kainulainen, Veera; Bowers, Jolene R.; Lemmer, Darrin; Engelthaler, David M.; Eklund, Kari K.; Facciotti, Federica; Satokari, Reetta (2020)
    Odoribacter splanchnicus, belonging to the order Bacteroidales, is a common, short-chain fatty acid producing member of the human intestinal microbiota. A decreased abundance of Odoribacter has been linked to different microbiota-associated diseases, such as non-alcoholic fatty liver disease, cystic fibrosis and inflammatory bowel disease (IBD). The type strain of O. splanchnicus has been genome-sequenced, but otherwise very little is known about this anaerobic bacterium. The species surfaces in many microbiota studies and, consequently, comprehension on its interactions with the host is needed. In this study, we isolated a novel strain of O. splanchnicus from a healthy fecal donor, identified it by genome sequencing and addressed its adhesive, epithelium reinforcing and immunoregulatory properties. Our results show that O. splanchnicus strain 57 is non-adherent to enterocytes or mucus, does not reinforce nor compromise Caco-2 monolayer integrity and most likely harbors penta-acylated, less endotoxic lipid A as part of its lipopolysaccharide (LPS) structure based on the lack of gene lpxM and in vitro results on low-level NF-κB activity. The studies by transmission electron microscopy revealed that O. splanchnicus produces outer membrane vesicles (OMV). O. splanchnicus cells, culture supernatant i.e., spent medium or OMVs did not induce interleukin-8 (IL-8) response in HT-29 enterocyte cells suggesting a very low proinflammatory capacity. On the contrary, the treatment of HT-29 cells with O. splanchnicus cells, spent medium or OMVs prior to exposure to Escherichia coli LPS elicited a significant decrease in IL-8 production as compared to E. coli LPS treatment alone. Moreover, O. splanchnicus spent supernatant induced IL-10 production by immune cells, suggesting anti-inflammatory activity. Our in vitro findings indicate that O. splanchnicus and its effector molecules transported in OMVs could potentially exert anti-inflammatory action in the gut epithelium. Taken together, O. splanchnicus seems to be a commensal with a primarily beneficial interaction with the host.
  • Munsterhjelm, Camilla Marianne; Nordgreen, Janicke; Aae, F.; Heinonen, Mari Leena; Valros, Anna Elisabet; Janczak, A. M. (2019)
    Poor health is associated with an increased risk of tail biting outbreaks in pigs. We propose that this is because illness changes social dynamics either by changing the behaviour of the sick pig towards its penmates, the behaviour of the healthy penmates towards the sick pig, or both. We tested the effect of immune stimulation (lipopolysaccharide (LPS) injection: O111:B4; 1.5 mu g kg(-1) IV) on social behaviour in gilts housed in triplets in a cross-over experiment. Each pen was subjected to the control treatment (all three pigs injected with saline) and then LPS treatment (one pig injected with LPS, two injected with saline), or vice versa. LPS injected pigs had a shift in social motivation and performed more tail- and ear- directed behaviour than saline pigs two days after injection. They seemed to fit the description of 'sick and grumpy'. This change was seen about 40 h after the signs of acute illness dissipated and was not accompanied by a similar increase in activity. We discuss possible mechanisms for this behavioural change in light of changes in neurotransmitter levels at three days after LPS injection described in a previous experiment.
  • Krusche, Johanna; Twardziok, Monika; Rehbach, Katharina; Böck, Andreas; Tsang, Miranda S.; Schröder, Paul C.; Kumbrink, Jörg; Kirchner, Thomas; Xing, Yuhan; Riedler, Josef; Dalphin, Jean-Charles; Pekkanen, Juha; Lauener, Roger; Roponen, Marjut; Li, Jing; Wong, Chun K.; Wong, Gary W.K.; Schaub, Bianca; Ege, Markus; Depner, Martin; Illi, Sabina; Loss, Georg J.; Renz, Harald; Pfefferle, Petra I.; Kabesch, Michael; Genuneit, Jon; Karvonen, Anne M.; Hyvärinen, Anne; Kirjavainen, Pirkka V.; Remes, Sami; Braun-Fahrländer, Charlotte; Roduit, Caroline; Frei, Remo; Kaulek, Vincent; Dalphin, Marie-Laure; Divaret-Chauveau, Amandine; Doekes, Gert (2019)
    Background: Childhood asthma prevalence is significantly greater in urban areas compared with rural/farm environments. Murine studies have shown that TNF-alpha-induced protein 3 (TNFAIP3; A20), an anti-inflammatory regulator of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B) signaling, mediates environmentally induced asthma protection. Objective: We aimed to determine the role of TNFAIP3 for asthma development in childhood and the immunomodulatory effects of environmental factors. Methods: In a representative selection of 250 of 2168 children from 2 prospective birth cohorts and 2 cross-sectional studies, we analyzed blood cells of healthy and asthmatic children from urban and rural/farm environments from Europe and China. PBMCs were stimulated ex vivo with dust from "asthma-protective'' farms or LPS. NF-kappa B signaling-related gene and protein expression was assessed in PBMCs and multiplex gene expression assays (NanoString Technologies) in isolated dendritic cells of schoolchildren and in cord blood mononuclear cells from newborns. Results: Anti-inflammatory TNFAIP3 gene and protein expression was consistently decreased, whereas proinflammatory Toll-like receptor 4 expression was increased in urban asthmatic patients (P <.05), reflecting their increased inflammatory status. Ex vivo farm dust or LPS stimulation restored TNFAIP3 expression to healthy levels in asthmatic patients and shifted NF-kappa B signaling-associated gene expression toward an anti-inflammatory state (P <.001). Farm/rural children had lower expression, indicating tolerance induction by continuous environmental exposure. Newborns with asthma at school age had reduced TNFAIP3 expression at birth, suggesting TNFAIP3 as a possible biomarker predicting subsequent asthma. Conclusion: Our data indicate TNFAIP3 as a key regulator during childhood asthma development and its environmentally mediated protection. Because environmental dust exposure conferred the anti-inflammatory effects, it might represent a promising future agent for asthma prevention and treatment.